diff --git a/protobuf/OWSSignalServiceProtos.proto b/protobuf/OWSSignalServiceProtos.proto
index 94b20de0a..814990829 100644
--- a/protobuf/OWSSignalServiceProtos.proto
+++ b/protobuf/OWSSignalServiceProtos.proto
@@ -133,13 +133,18 @@ message SyncMessage {
 }
 
 message AttachmentPointer {
-  optional fixed64 id          = 1;
-  optional string  contentType = 2;
-  optional bytes   key         = 3;
-  optional uint32  size        = 4;
-  optional bytes   thumbnail   = 5;
-  optional bytes   digest      = 6;
-  optional string  fileName    = 7;
+    enum Flags {
+        VOICE_MESSAGE = 1;
+    }
+
+    optional fixed64 id = 1;
+    optional string contentType = 2;
+    optional bytes key = 3;
+    optional uint32 size = 4;
+    optional bytes thumbnail = 5;
+    optional bytes digest = 6;
+    optional string fileName = 7;
+    optional uint32 flags = 8;
 }
 
 message GroupContext {
diff --git a/src/Messages/Attachments/OWSAttachmentsProcessor.m b/src/Messages/Attachments/OWSAttachmentsProcessor.m
index 05a526951..1cd27dc0e 100644
--- a/src/Messages/Attachments/OWSAttachmentsProcessor.m
+++ b/src/Messages/Attachments/OWSAttachmentsProcessor.m
@@ -79,12 +79,21 @@ static const CGFloat kAttachmentDownloadProgressTheta = 0.001f;
         // digest will be empty for old clients.
         NSData *digest = attachmentProto.hasDigest ? attachmentProto.digest : nil;
 
+        TSAttachmentType attachmentType = TSAttachmentTypeDefault;
+        if ([attachmentProto hasFlags]) {
+            UInt32 flags = attachmentProto.flags;
+            if ((flags & (UInt32)OWSSignalServiceProtosAttachmentPointerFlagsVoiceMessage) > 0) {
+                attachmentType = TSAttachmentTypeVoiceMessage;
+            }
+        }
+
         TSAttachmentPointer *pointer = [[TSAttachmentPointer alloc] initWithServerId:attachmentProto.id
                                                                                  key:attachmentProto.key
                                                                               digest:digest
                                                                          contentType:attachmentProto.contentType
                                                                                relay:relay
-                                                                            filename:attachmentProto.fileName];
+                                                                            filename:attachmentProto.fileName
+                                                                      attachmentType:attachmentType];
 
         [attachmentIds addObject:pointer.uniqueId];
 
diff --git a/src/Messages/Attachments/TSAttachment.h b/src/Messages/Attachments/TSAttachment.h
index 9fd8d3f29..d26bc74c4 100644
--- a/src/Messages/Attachments/TSAttachment.h
+++ b/src/Messages/Attachments/TSAttachment.h
@@ -6,6 +6,11 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+typedef NS_ENUM(NSUInteger, TSAttachmentType) {
+    TSAttachmentTypeDefault = 0,
+    TSAttachmentTypeVoiceMessage = 1,
+};
+
 @interface TSAttachment : TSYapDatabaseObject {
 
 @protected
@@ -24,6 +29,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, readonly) NSString *contentType;
 
 @property (atomic, readwrite) BOOL isDownloaded;
+@property (nonatomic) TSAttachmentType attachmentType;
 
 // This constructor is used for new instances of TSAttachmentPointer,
 // i.e. undownloaded incoming attachments.
@@ -43,6 +49,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)upgradeFromAttachmentSchemaVersion:(NSUInteger)attachmentSchemaVersion;
 
+- (BOOL)isVoiceMessage;
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/src/Messages/Attachments/TSAttachment.m b/src/Messages/Attachments/TSAttachment.m
index cd92bbf38..53f3f830b 100644
--- a/src/Messages/Attachments/TSAttachment.m
+++ b/src/Messages/Attachments/TSAttachment.m
@@ -110,6 +110,11 @@ NSUInteger const TSAttachmentSchemaVersion = 3;
     return attachmentString;
 }
 
+- (BOOL)isVoiceMessage
+{
+    return self.attachmentType == TSAttachmentTypeVoiceMessage;
+}
+
 #pragma mark - Logging
 
 + (NSString *)tag
diff --git a/src/Messages/Attachments/TSAttachmentPointer.h b/src/Messages/Attachments/TSAttachmentPointer.h
index 80201766d..106a1ad88 100644
--- a/src/Messages/Attachments/TSAttachmentPointer.h
+++ b/src/Messages/Attachments/TSAttachmentPointer.h
@@ -24,7 +24,8 @@ typedef NS_ENUM(NSUInteger, TSAttachmentPointerState) {
                           digest:(nullable NSData *)digest
                      contentType:(NSString *)contentType
                            relay:(NSString *)relay
-                        filename:(nullable NSString *)filename NS_DESIGNATED_INITIALIZER;
+                        filename:(nullable NSString *)filename
+                  attachmentType:(TSAttachmentType)attachmentType NS_DESIGNATED_INITIALIZER;
 
 @property (nonatomic, readonly) NSString *relay;
 @property (nonatomic, readonly, nullable) NSString *filename;
diff --git a/src/Messages/Attachments/TSAttachmentPointer.m b/src/Messages/Attachments/TSAttachmentPointer.m
index 7097a204a..a2998a5a5 100644
--- a/src/Messages/Attachments/TSAttachmentPointer.m
+++ b/src/Messages/Attachments/TSAttachmentPointer.m
@@ -31,6 +31,7 @@ NS_ASSUME_NONNULL_BEGIN
                      contentType:(NSString *)contentType
                            relay:(NSString *)relay
                         filename:(nullable NSString *)filename
+                  attachmentType:(TSAttachmentType)attachmentType
 {
     self = [super initWithServerId:serverId encryptionKey:key contentType:contentType];
     if (!self) {
@@ -41,6 +42,7 @@ NS_ASSUME_NONNULL_BEGIN
     _state = TSAttachmentPointerStateEnqueued;
     _relay = relay;
     _filename = filename;
+    self.attachmentType = attachmentType;
 
     return self;
 }
diff --git a/src/Messages/Attachments/TSAttachmentStream.m b/src/Messages/Attachments/TSAttachmentStream.m
index d29a83479..9c6799b4a 100644
--- a/src/Messages/Attachments/TSAttachmentStream.m
+++ b/src/Messages/Attachments/TSAttachmentStream.m
@@ -44,6 +44,7 @@ NS_ASSUME_NONNULL_BEGIN
     // attachments which don't need to be uploaded.
     _isUploaded = YES;
     _filename = pointer.filename;
+    self.attachmentType = pointer.attachmentType;
 
     return self;
 }
diff --git a/src/Messages/Interactions/TSOutgoingMessage.h b/src/Messages/Interactions/TSOutgoingMessage.h
index af505589a..b711bcd0d 100644
--- a/src/Messages/Interactions/TSOutgoingMessage.h
+++ b/src/Messages/Interactions/TSOutgoingMessage.h
@@ -57,6 +57,11 @@ typedef NS_ENUM(NSInteger, TSGroupMetaMessage) {
                     attachmentIds:(NSMutableArray<NSString *> *)attachmentIds
                  expiresInSeconds:(uint32_t)expiresInSeconds;
 
+- (instancetype)initWithTimestamp:(uint64_t)timestamp
+                         inThread:(nullable TSThread *)thread
+                   isVoiceMessage:(BOOL)isVoiceMessage
+                 expiresInSeconds:(uint32_t)expiresInSeconds;
+
 - (instancetype)initWithTimestamp:(uint64_t)timestamp
                          inThread:(nullable TSThread *)thread
                       messageBody:(nullable NSString *)body
@@ -95,6 +100,8 @@ typedef NS_ENUM(NSInteger, TSGroupMetaMessage) {
  */
 @property (nonatomic, readonly) BOOL isLegacyMessage;
 
+@property (nonatomic, readonly) BOOL isVoiceMessage;
+
 /**
  * Signal Identifier (e.g. e164 number) or nil if in a group thread.
  */
diff --git a/src/Messages/Interactions/TSOutgoingMessage.m b/src/Messages/Interactions/TSOutgoingMessage.m
index a16995468..471f63071 100644
--- a/src/Messages/Interactions/TSOutgoingMessage.m
+++ b/src/Messages/Interactions/TSOutgoingMessage.m
@@ -22,6 +22,7 @@ NSString *const kTSOutgoingMessageSentRecipientAll = @"kTSOutgoingMessageSentRec
 @property (atomic) NSString *customMessage;
 @property (atomic) NSString *mostRecentFailureText;
 @property (atomic) BOOL wasDelivered;
+
 // For outgoing, non-legacy group messages sent from this client, this
 // contains the list of recipients to whom the message has been sent.
 //
@@ -110,6 +111,24 @@ NSString *const kTSOutgoingMessageSentRecipientAll = @"kTSOutgoingMessageSentRec
                    expireStartedAt:0];
 }
 
+- (instancetype)initWithTimestamp:(uint64_t)timestamp
+                         inThread:(nullable TSThread *)thread
+                   isVoiceMessage:(BOOL)isVoiceMessage
+                 expiresInSeconds:(uint32_t)expiresInSeconds
+{
+    self = [self initWithTimestamp:timestamp
+                          inThread:thread
+                       messageBody:nil
+                     attachmentIds:[NSMutableArray new]
+                  expiresInSeconds:expiresInSeconds
+                   expireStartedAt:0];
+    if (self) {
+        _isVoiceMessage = isVoiceMessage;
+    }
+
+    return self;
+}
+
 - (instancetype)initWithTimestamp:(uint64_t)timestamp
                          inThread:(nullable TSThread *)thread
                       messageBody:(nullable NSString *)body
@@ -452,7 +471,7 @@ NSString *const kTSOutgoingMessageSentRecipientAll = @"kTSOutgoingMessageSentRec
     [builder setFileName:filename];
     [builder setKey:attachmentStream.encryptionKey];
     [builder setDigest:attachmentStream.digest];
-
+    [builder setFlags:(self.isVoiceMessage ? OWSSignalServiceProtosAttachmentPointerFlagsVoiceMessage : 0)];
     return [builder build];
 }
 
diff --git a/src/Messages/OWSSignalServiceProtos.pb.h b/src/Messages/OWSSignalServiceProtos.pb.h
index 9ef8c1214..8db11c83b 100644
--- a/src/Messages/OWSSignalServiceProtos.pb.h
+++ b/src/Messages/OWSSignalServiceProtos.pb.h
@@ -1,4 +1,6 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
 
 #import <ProtocolBuffers/ProtocolBuffers.h>
 
@@ -123,6 +125,13 @@ typedef NS_ENUM(SInt32, OWSSignalServiceProtosSyncMessageRequestType) {
 BOOL OWSSignalServiceProtosSyncMessageRequestTypeIsValidValue(OWSSignalServiceProtosSyncMessageRequestType value);
 NSString *NSStringFromOWSSignalServiceProtosSyncMessageRequestType(OWSSignalServiceProtosSyncMessageRequestType value);
 
+typedef NS_ENUM(SInt32, OWSSignalServiceProtosAttachmentPointerFlags) {
+    OWSSignalServiceProtosAttachmentPointerFlagsVoiceMessage = 1,
+};
+
+BOOL OWSSignalServiceProtosAttachmentPointerFlagsIsValidValue(OWSSignalServiceProtosAttachmentPointerFlags value);
+NSString *NSStringFromOWSSignalServiceProtosAttachmentPointerFlags(OWSSignalServiceProtosAttachmentPointerFlags value);
+
 typedef NS_ENUM(SInt32, OWSSignalServiceProtosGroupContextType) {
   OWSSignalServiceProtosGroupContextTypeUnknown = 0,
   OWSSignalServiceProtosGroupContextTypeUpdate = 1,
@@ -1290,6 +1299,7 @@ NSString *NSStringFromOWSSignalServiceProtosGroupContextType(OWSSignalServicePro
 #define AttachmentPointer_thumbnail @"thumbnail"
 #define AttachmentPointer_digest @"digest"
 #define AttachmentPointer_fileName @"fileName"
+#define AttachmentPointer_flags @"flags"
 @interface OWSSignalServiceProtosAttachmentPointer : PBGeneratedMessage<GeneratedMessageProtocol> {
 @private
   BOOL hasId_:1;
@@ -1299,6 +1309,7 @@ NSString *NSStringFromOWSSignalServiceProtosGroupContextType(OWSSignalServicePro
   BOOL hasThumbnail_:1;
   BOOL hasDigest_:1;
   BOOL hasSize_:1;
+  BOOL hasFlags_ : 1;
   UInt64 id;
   NSString* contentType;
   NSString* fileName;
@@ -1306,6 +1317,7 @@ NSString *NSStringFromOWSSignalServiceProtosGroupContextType(OWSSignalServicePro
   NSData* thumbnail;
   NSData* digest;
   UInt32 size;
+  UInt32 flags;
 }
 - (BOOL) hasId;
 - (BOOL) hasContentType;
@@ -1314,6 +1326,7 @@ NSString *NSStringFromOWSSignalServiceProtosGroupContextType(OWSSignalServicePro
 - (BOOL) hasThumbnail;
 - (BOOL) hasDigest;
 - (BOOL) hasFileName;
+- (BOOL)hasFlags;
 @property (readonly) UInt64 id;
 @property (readonly, strong) NSString* contentType;
 @property (readonly, strong) NSData* key;
@@ -1321,6 +1334,7 @@ NSString *NSStringFromOWSSignalServiceProtosGroupContextType(OWSSignalServicePro
 @property (readonly, strong) NSData* thumbnail;
 @property (readonly, strong) NSData* digest;
 @property (readonly, strong) NSString* fileName;
+@property (readonly) UInt32 flags;
 
 + (instancetype) defaultInstance;
 - (instancetype) defaultInstance;
@@ -1391,6 +1405,11 @@ NSString *NSStringFromOWSSignalServiceProtosGroupContextType(OWSSignalServicePro
 - (NSString*) fileName;
 - (OWSSignalServiceProtosAttachmentPointerBuilder*) setFileName:(NSString*) value;
 - (OWSSignalServiceProtosAttachmentPointerBuilder*) clearFileName;
+
+- (BOOL)hasFlags;
+- (UInt32)flags;
+- (OWSSignalServiceProtosAttachmentPointerBuilder *)setFlags:(UInt32)value;
+- (OWSSignalServiceProtosAttachmentPointerBuilder *)clearFlags;
 @end
 
 #define GroupContext_id @"id"
diff --git a/src/Messages/OWSSignalServiceProtos.pb.m b/src/Messages/OWSSignalServiceProtos.pb.m
index 5c0598aa2..3325006de 100644
--- a/src/Messages/OWSSignalServiceProtos.pb.m
+++ b/src/Messages/OWSSignalServiceProtos.pb.m
@@ -1,4 +1,6 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
 
 #import "OWSSignalServiceProtos.pb.h"
 // @@protoc_insertion_point(imports)
@@ -5375,6 +5377,7 @@ static OWSSignalServiceProtosSyncMessageRead* defaultOWSSignalServiceProtosSyncM
 @property (strong) NSData* thumbnail;
 @property (strong) NSData* digest;
 @property (strong) NSString* fileName;
+@property UInt32 flags;
 @end
 
 @implementation OWSSignalServiceProtosAttachmentPointer
@@ -5428,6 +5431,15 @@ static OWSSignalServiceProtosSyncMessageRead* defaultOWSSignalServiceProtosSyncM
   hasFileName_ = !!_value_;
 }
 @synthesize fileName;
+- (BOOL)hasFlags
+{
+    return !!hasFlags_;
+}
+- (void)setHasFlags:(BOOL)_value_
+{
+    hasFlags_ = !!_value_;
+}
+@synthesize flags;
 - (instancetype) init {
   if ((self = [super init])) {
     self.id = 0L;
@@ -5437,6 +5449,7 @@ static OWSSignalServiceProtosSyncMessageRead* defaultOWSSignalServiceProtosSyncM
     self.thumbnail = [NSData data];
     self.digest = [NSData data];
     self.fileName = @"";
+    self.flags = 0;
   }
   return self;
 }
@@ -5477,6 +5490,9 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
   if (self.hasFileName) {
     [output writeString:7 value:self.fileName];
   }
+  if (self.hasFlags) {
+      [output writeUInt32:8 value:self.flags];
+  }
   [self.unknownFields writeToCodedOutputStream:output];
 }
 - (SInt32) serializedSize {
@@ -5507,6 +5523,9 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
   if (self.hasFileName) {
     size_ += computeStringSize(7, self.fileName);
   }
+  if (self.hasFlags) {
+      size_ += computeUInt32Size(8, self.flags);
+  }
   size_ += self.unknownFields.serializedSize;
   memoizedSerializedSize = size_;
   return size_;
@@ -5563,6 +5582,9 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
   if (self.hasFileName) {
     [output appendFormat:@"%@%@: %@\n", indent, @"fileName", self.fileName];
   }
+  if (self.hasFlags) {
+      [output appendFormat:@"%@%@: %@\n", indent, @"flags", [NSNumber numberWithInteger:self.flags]];
+  }
   [self.unknownFields writeDescriptionTo:output withIndent:indent];
 }
 - (void) storeInDictionary:(NSMutableDictionary *)dictionary {
@@ -5587,6 +5609,9 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
   if (self.hasFileName) {
     [dictionary setObject: self.fileName forKey: @"fileName"];
   }
+  if (self.hasFlags) {
+      [dictionary setObject:[NSNumber numberWithInteger:self.flags] forKey:@"flags"];
+  }
   [self.unknownFields storeInDictionary:dictionary];
 }
 - (BOOL) isEqual:(id)other {
@@ -5597,22 +5622,19 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
     return NO;
   }
   OWSSignalServiceProtosAttachmentPointer *otherMessage = other;
-  return
-      self.hasId == otherMessage.hasId &&
-      (!self.hasId || self.id == otherMessage.id) &&
-      self.hasContentType == otherMessage.hasContentType &&
-      (!self.hasContentType || [self.contentType isEqual:otherMessage.contentType]) &&
-      self.hasKey == otherMessage.hasKey &&
-      (!self.hasKey || [self.key isEqual:otherMessage.key]) &&
-      self.hasSize == otherMessage.hasSize &&
-      (!self.hasSize || self.size == otherMessage.size) &&
-      self.hasThumbnail == otherMessage.hasThumbnail &&
-      (!self.hasThumbnail || [self.thumbnail isEqual:otherMessage.thumbnail]) &&
-      self.hasDigest == otherMessage.hasDigest &&
-      (!self.hasDigest || [self.digest isEqual:otherMessage.digest]) &&
-      self.hasFileName == otherMessage.hasFileName &&
-      (!self.hasFileName || [self.fileName isEqual:otherMessage.fileName]) &&
-      (self.unknownFields == otherMessage.unknownFields || (self.unknownFields != nil && [self.unknownFields isEqual:otherMessage.unknownFields]));
+  return self.hasId == otherMessage.hasId && (!self.hasId || self.id == otherMessage.id)
+      && self.hasContentType == otherMessage.hasContentType
+      && (!self.hasContentType || [self.contentType isEqual:otherMessage.contentType])
+      && self.hasKey == otherMessage.hasKey && (!self.hasKey || [self.key isEqual:otherMessage.key])
+      && self.hasSize == otherMessage.hasSize && (!self.hasSize || self.size == otherMessage.size)
+      && self.hasThumbnail == otherMessage.hasThumbnail
+      && (!self.hasThumbnail || [self.thumbnail isEqual:otherMessage.thumbnail])
+      && self.hasDigest == otherMessage.hasDigest && (!self.hasDigest || [self.digest isEqual:otherMessage.digest])
+      && self.hasFileName == otherMessage.hasFileName
+      && (!self.hasFileName || [self.fileName isEqual:otherMessage.fileName]) && self.hasFlags == otherMessage.hasFlags
+      && (!self.hasFlags || self.flags == otherMessage.flags)
+      && (self.unknownFields == otherMessage.unknownFields
+             || (self.unknownFields != nil && [self.unknownFields isEqual:otherMessage.unknownFields]));
 }
 - (NSUInteger) hash {
   __block NSUInteger hashCode = 7;
@@ -5637,11 +5659,33 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
   if (self.hasFileName) {
     hashCode = hashCode * 31 + [self.fileName hash];
   }
+  if (self.hasFlags) {
+      hashCode = hashCode * 31 + [[NSNumber numberWithInteger:self.flags] hash];
+  }
   hashCode = hashCode * 31 + [self.unknownFields hash];
   return hashCode;
 }
 @end
 
+BOOL OWSSignalServiceProtosAttachmentPointerFlagsIsValidValue(OWSSignalServiceProtosAttachmentPointerFlags value)
+{
+    switch (value) {
+        case OWSSignalServiceProtosAttachmentPointerFlagsVoiceMessage:
+            return YES;
+        default:
+            return NO;
+    }
+}
+NSString *NSStringFromOWSSignalServiceProtosAttachmentPointerFlags(OWSSignalServiceProtosAttachmentPointerFlags value)
+{
+    switch (value) {
+        case OWSSignalServiceProtosAttachmentPointerFlagsVoiceMessage:
+            return @"OWSSignalServiceProtosAttachmentPointerFlagsVoiceMessage";
+        default:
+            return nil;
+    }
+}
+
 @interface OWSSignalServiceProtosAttachmentPointerBuilder()
 @property (strong) OWSSignalServiceProtosAttachmentPointer* resultAttachmentPointer;
 @end
@@ -5701,6 +5745,9 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
   if (other.hasFileName) {
     [self setFileName:other.fileName];
   }
+  if (other.hasFlags) {
+      [self setFlags:other.flags];
+  }
   [self mergeUnknownFields:other.unknownFields];
   return self;
 }
@@ -5750,6 +5797,10 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
         [self setFileName:[input readString]];
         break;
       }
+      case 64: {
+          [self setFlags:[input readUInt32]];
+          break;
+      }
     }
   }
 }
@@ -5865,6 +5916,26 @@ static OWSSignalServiceProtosAttachmentPointer* defaultOWSSignalServiceProtosAtt
   resultAttachmentPointer.fileName = @"";
   return self;
 }
+- (BOOL)hasFlags
+{
+    return resultAttachmentPointer.hasFlags;
+}
+- (UInt32)flags
+{
+    return resultAttachmentPointer.flags;
+}
+- (OWSSignalServiceProtosAttachmentPointerBuilder *)setFlags:(UInt32)value
+{
+    resultAttachmentPointer.hasFlags = YES;
+    resultAttachmentPointer.flags = value;
+    return self;
+}
+- (OWSSignalServiceProtosAttachmentPointerBuilder *)clearFlags
+{
+    resultAttachmentPointer.hasFlags = NO;
+    resultAttachmentPointer.flags = 0;
+    return self;
+}
 @end
 
 @interface OWSSignalServiceProtosGroupContext ()